Effect of Filtering and Compression on Right Ear Advantage

Abstract

Right ear advantage is consistent finding in dichotic tests, referring to more scores obtained for the right ear compared to the left ear for verbal stimulus administered using dichotic paradigm. Dichotic tests incorporate wide range of stimuli, from CV to sentences and the resulting ear advantage obtained vary with the type of stimulus used. Effect of linguistic influence on right ear advantage is not clearly reported in the literature. Current study investigated the effect of reducing redundancy achieved through filtering and compression on monosyllabic words, on the right ear advantage. Study incorporated 120 native Kannada speaking participants in the age range of 18-36 years, who were right handed and had hearing sensitivity within normal limits. They were divided into three groups based on their age (18-24; 24-30; 30-36 years). The participants were required to repeat the dichotically presented stimuli. Each participant was randomly evaluated using four different dichotic stimuli list which included untruncated, compressed, filtered and compressed+filtered stimuli. Results revealed right ear scores to be significantly higher compared to the left ear. Results of right ear advantage showed an increasing trend across the conditions with lowest scores for unaltered condition and highest for the compressed+ filtered condition. There was also no difference in the right ear advantage across the three age groups. It was concluded that there was a clear effect of linguistic load on right ear advantage, with greater advantage for the right ear for stimulus having lesser linguistic load. Also, age does not have an effect on the right ear advantage, especially for the age range of 18-36 years.